Light stabilizer packages for partial paint applications

ABSTRACT

A light stabilizer package is disclosed. The light stabilizer package comprises a monomeric HALS having a pKa of no greater than 7, an ultraviolet light absorber and, optionally, a polymeric HALS having a pKa of less than 7. The light stabilizer package may be blended with a thermoplastic olefin to form a moldable light stable composition. An article comprising the moldable light stable composition may have an exterior surface that is at least partially coated.

This application is a Continuation of application Ser. No. 08/461,999filed Jun. 5, 1995 now Pat. No. 5,733,956, which, in turn, was aContinuation of application Ser. No. 08/036,607 filed Mar. 24, 1993.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to light stabilizer packages which arecapable of being blended with organic materials such as thermoplasticolefinic elastomer compounds (TPOs) to impart resistance to degradationfrom ultraviolet light to such materials. Compositions of these organicmaterials and light stabilizer packages can be molded into articleswhich are light stable while also being receptive for coatings of acidcatalyst activated single component paint (1 pack paint) systems. Inaddition, the present invention relates the articles formed from thesemoldable light stabilized compositions.

2. Description of the Background Art

Organic materials in general, and specifically synthetic polymers, whilewidely utilized, have relatively poor light stability. For example,olefinic elastomer compounds tend to undergo severe deterioration whenexposed to light such as sunlight or ultraviolet rays. Light stabilizersthat had previously been used to increase the resistance of sucholefinic elastomer compounds against light included ultraviolet lightabsorbers such as benzotriazole compounds and benzophenone compounds. Itwas later found that N-unsubstituted polyalkylpiperidine Hindered AmineLight Stabilizers (hereinafter HALS's) such as, for example, thosedisclosed in U.S. Pat. No. 4,241,208 of Murayama et al., providesuperior protection to olefinic elastomer compounds againstphoto-induced degradation as compared to the ultraviolet lightabsorbers. Currently, photo-induced degradation of olefinic elastomercompounds such as TPOs is combatted by adding HALS to the coatingsapplied to an olefinic elastomeric compound otherwise formulated withoutany stabilizers or by including basic HALS in the olefinic elastomericformulation.

When an HALS is added to a coating that is applied to a molded TPOarticle, the entire article must be coated in order to stabilize allportions of the article against ultraviolet degradation. An example of acomposition of HALS that can be added to a coating that can be appliedto a TPO article is described in the brochure distributed by Ciba-GeigyCorporation entitled "Tinuvin® 440 UV Light Stabilizer for Acidcatalyzed Coatings" wherein a composition of 1.0%-2.0% Tinuvin® 440 byweight, based on the coating resin solid and of 2.0%-4.0% Tinuvin® 1130by weight, based on the coating resin solids, is disclosed.

Further, it has been found that when a basic HALS compound is includedas part of a TPO formulation to provide light stability to a TPO, theTPO either must remain unpainted or can only be painted with twocomponent paint systems. It has been found that when a basic HALScompound is added to a TPO formulation to provide light stability to aTPO, the TPO cannot effectively be coated with a 1 pack paint systembecause such paint systems react with the compound so that the paintdoes not cure properly and poorly adheres to the substrate. In addition,for 1 pack paint clearcoat systems, the light stabilizing effect of theHALS compound might be neutralized, resulting in photo-degradation ofthe TPO. It is believed that the reason for this reaction is becausebasic HALS compounds react with the acidic organic pigments and curativeagents of the 1 pack paint systems. Other factors affecting the paintadhesion are the affinity behavior among the components of the TPOformulation, the migration characteristics of the additives to the TPOformulation, the volatility of the additives to the TPO formulation andthe thermal stability of the total system. The same problem has not beenobserved with two component paint systems since such systems are notacidic.

As noted above, when a TPO is coated with an HALS-containing coating,the entire molded TPO article must be coated in order to preventultraviolet degradation of any portion thereof. Further, current TPOstabilizer systems included as part of a TPO formulation are fullyoperational only when molded TPO articles do not have to be painted with1 pack paint systems. It is often desirable for articles which aremolded from such TPO formulations to be partially painted for decorativeor aesthetic effects. For example, the exterior portion of automotivebumpers for certain models are made from molded TPO compositions whichinclude conventional stabilizers, and which are pigmented to the desiredcolor. These bumpers cannot be successfully coated with 1 pack paintsystems for the reasons explained above. However, automobile designerswould like to enhance the appearances of such bumpers by providing a 1pack coating on portions thereof, while retaining the low weight andresiliency of the TPO. This cannot be accomplished with conventional TPOformulations.

Two solutions to this problem are currently known, First, it is possibleto paint these articles with a two-component system, such as apolyurethane, but this results in additional process steps for coatingthe article as well as greater cost for the coating materials.Alternatively, it is possible to formulate the TPO without anystabilizers, but this would require coating of the entire article with acoating containing HALS, or else the uncoated areas would degrade overtime when exposed to ultraviolet light.

Accordingly, a need exists for a stabilizer system that can be added toa TPO formulation to impart ultraviolet light resistance to the TPOformulations while also enabling such formulations to be unreactivetoward 1-pack paint systems so that portions of the articles made fromthe TPOs can be painted.

SUMMARY OF THE INVENTION

The invention relates to a light stabilizer package for TPOs. Thepackage comprises a monomeric HALS having a basicity or pKa of nogreater than 7, an ultraviolet light absorbing agent and a polymericHALS having a basicity or pka of less than 7. Preferably, the monomericlight stabilizer is a piperidine derivative or a piperazinone having abasicity or pKa of 6 or less. Preferably, the ultraviolet lightabsorbing agent is benzotriazole or benzophenone compound. Preferablythe polymeric HALS is a piperidine polymer having a basicity or pKa of6.5 or less. Preferably, the monomeric light stabilizer is present in anamount of between about 30 and 65%, the light absorber is present in anamount of between about 25 and 45% and the polymeric light absorber ispresent in an amount of between about 10 and 35%. Preferably, themonomeric light stabilizer is present in an amount that is equal to orgreater than that of the ultraviolet light absorbing agent or thepolymeric light stabilizer. The three components may be present insubstantially the same amount.

The invention further relates to a light stabilized compositioncomprising a TPO and a light stabilizer package. Preferably, the lightstabilizer package comprises a monomeric HALS light stabilizer having abasicity or pKa of no more than 7 in combination with an ultravioletlight absorbing agent. Preferably, the light stabilizer is a piperidinederivative having a basicity or pKa of 6 or less. Preferably, theultraviolet light absorbing agent is benzotriazole or benzophenonecompound. Preferably, the light stabilizer is present in amount of about40-90% of the light stabilizer package and the ultraviolet lightabsorbing agent is present in an amount of between 10 and 60% of thelight stabilizer package. Preferably, the light stabilizer is present inan amount equal to or greater than the ultraviolet light absorbingagent. The package may also comprise a polymeric HALS having a basicityor pKa of less than 7. Preferably the polymeric HALS is a piperidinepolymer having a basicity or pKa of 6.5 or less. Preferably, in thisthree component package the monomeric light stabilizer is present in anamount of between about 30 and 80% of the light stabilizer package, thelight absorber is present in an amount of between about 10 and 45% ofthe light stabilizer package and the polymeric light absorber is presentin an amount of between about 10 and 35% of the light stabilizerpackage. Preferably, the monomeric light stabilizer is present in anamount that is equal to or greater than that of the polymeric lightstabilizer. All three components may be present in substantially thesame amount.

The light stabilizer package may be present in an amount of about 0.4 to2% by weight of the light stabilized composition.

The invention further relates to an article having an exterior surfacecomprising a molded light stabilized polymeric composition as describedabove, and a coating upon a portion of the exterior surface thereof.Preferably, the composition comprises a TPO and a light stabilizerpackage. The light stabilizer package may comprise a monomeric HALShaving a basicity or pKa of no greater than 7 in combination with anultraviolet light absorbing agent. The package may also include apolymeric HALS having a basicity or pKa of less than 7. Preferably, thecoating is a one-pack coating and, more preferably, comprises anacrylic, alkyd, melamine, polyester, thermoplastic or elastomericmaterial. The light stabilizer package may be present in an amount ofabout 0.4 to 2% by weight of the composition. Preferably, the TPOcomprises a homopolymer and a copolymer of CH₂ ═C--(R)₂, where R is H ora C₁ -C₆ straight or branched alkyl moiety. Preferably, the TPOcomprises a blend of at least a homopolymer and a copolymer. Morepreferably, the TPO comprises crystalline polypropylene or polyethyleneand amorphous ethylene-propylene copolymer rubber or ethylene-propyleneterpolymer resin, or mixtures thereof either from an intensive mixingprocess or from sequential polymerization in reactors.

DETAILED DESCRIPTION OF THE INVENTION

The light stabilizer packages of the present invention provide lightstability to TPO compositions containing them in addition to beingunreactive with 1-pack acid catalyzed paint systems. The package is athree-component package which comprises a monomeric HALS having abasicity or pKa of no more than 7, an ultraviolet light absorbing agentand a polymeric HALS having a basicity or pKa of less than 7.

A TPO is a polyolefinic resin which can be heated and softenedinnumerable times without suffering any basic alteration incharacteristics. A polyolefin is a polymer, or union, of compounds thatare unsaturated, chemically active hydrocarbons with one carbon-carbondouble bond. Examples of olefins include polyethylene, polypropylene,etc. Polyolefins result from the union of such olefins. Polyolefins canbe the result of blending the same or different olefins. Examples ofthermoplastic polyolefinic formulations and their formulations can befound in, for example, U.S. Pat. Nos. 4,945,005 and 4,997,720

The monomeric HALS of the present invention have pKa of no greater than7. Thus, the monomeric HALS's are preferably acidic in nature but may beneutral. Preferably, the monomeric HALS of the present invention has apKa of 6 or less. The pKa may be 5 or less, 4.2 or less or even 2.6 orless. The monomeric HALS is preferably a piperidine derivative or apiperazinone derivative. More preferably, the monomeric HALS is anN-substituted polyalkylpiperidine or N-substituted polyalkylpiperazinonederivative, and most preferably is a secondary or tertiary N-substitutedpolyalkylpiperidine or a secondary or tertiary N-substitutedpolyalkylpiperazinone such as, for example, an N--H tetramethylpiperidine derivative, an o-octyl analogue of an N--H tetramethylpiperidine derivative, a tetramethylpiperazinone, etc. Examples of themonomeric HALS of the present invention include Tinuvin® 440 ofCiba-Geigy Corporation, a piperidine derivative HALS having a pKa of2.5; Tinuvin® 123 of Ciba-Geigy Corporation, an o-octyl analogue of theNH HALS having a pKa of 4.2; Goodrite 3159® of B.F. Goodrich Co., atetramethylpiperazinone HALS having a pKa of 6; and Cyasorb® UV-3668 ofCytec Industries, a derivative of a tetramethyl piperidine having a pKaof 5.0.

The UV light absorbers of the present invention can be any of thepresently known UV light absorbers. Presently known UV light absorbersinclude, for example, 2-(2'-hydroxyphenyl) benzotriazoles, 2-hydroxybenzophenones, etc. Examples of benzotriazole UV absorbers of thepresent invention are, for example,2-(2'-hydroxy-3',5'-di-t-butyl)-5-chlorobenzotriazole such as Tinuvin®327 of Ciba-Geigy Corporation and 2-[2'-hydroxy-3',5'-(di-t-amyl)phenyl]-benzotriazole such as Tinuvin® 328 of Ciba-GeigyCorporation. An example of a benzophenone UV absorber of the presentinvention is, for example, 2-hydroxyl-4-n-octylbenzophenone such asCyasorb® UV 531 of Cytec Industries.

The polymeric HALS of the present invention having a basicity or pKa ofless than 7 is added to the package to form a three component lightstabilizer package. Examples of polymeric HALS that can be used in thepresent invention include Tinuvin® 622 of Ciba-Geigy Corp., having a pKaof 6.5.

Preferably, the monomeric HALS is added in an amount equal to or greaterthan both the ultraviolet light absorber and the polymeric HALS. In thisthree component light stabilizer package, the monomeric HALS ispreferably present in an amount of from about 30-80%, the ultravioletlight absorber is preferably present in an amount of from about 10-45%of the light stabilizer package and the polymeric HALS is added in anamount of about 10-35% of the light stabilizer package. In a preferredembodiment, all three components are present in substantially the sameamount.

The characteristics of monomeric and polymeric HALS is that may be usedin the present invention are compared to other HALS that aretraditionally used as light stabilizers in Table 1.

                  TABLE I                                                         ______________________________________                                        Hindered Amine Light Stabilizers                                                                        Functional                                            Hindered Amine.sup.1 pKa Group M.W.                                         ______________________________________                                        Chimassorb ® 944                                                                       9.7      N--H       >2500                                          Chimassorb ® 119 9.2 N--CH.sub.3 2286                                     Tinuvin ® 770 9.0 N--H 481                                                Tinuvin ® 144 8.5 N--CH.sub.3 685                                         Tinuvin ® 622 6.5 N-R >2500                                               Tinuvin ® 123 4.2 N--O--C.sub.8 H.sub.17 737                              Tinuvin ® 440 2.5 N--COCH.sub.3 435                                     ______________________________________                                         .sup.1 All Hindered Amines in Table I are products of CibaGeigy               Corporation.                                                             

The pKa values of Tinuvin® 622 and Tinuvin® 440 render the lightstabilizer package of the present invention less basic. Thus, the lightstabilizer package of the present invention will not readily react withthe acid in the 1-pack paint systems, unlike, for example, Tinuvin® 770and Chimassorb® 944, which are very basic. Further, the HALS of thepresent invention are slower to migrate to the surface of the moldedparts, which migration affects paint adhesion, than for example,Tinuvin® 770.

Examples of the percentages of the components that can be used in thelight stabilizer packages of the present invention are described inTable II.

                  TABLE II                                                        ______________________________________                                        LIGHT STABILIZER PACKAGES                                                       (% of total package)                                                            Component    Package 1  Package 2                                                                            Package 3                                  ______________________________________                                        Monomeric HALS                                                                             33.3       42.8     42.8                                           UV Absorber 33.3 42.8 28.6                                                    Polymeric HALS 33.3 14.3 28.6                                               ______________________________________                                    

As noted above, the monomeric HALS is present in an amount which isequal to or greater than the amounts of either of the light absorber orpolymeric HALS. Thus, the monomeric HALS may be present in a relativeamount of between and between about 30% and 80% of the three componentpackage. The light absorbing agent may be present in an amount ofbetween about 10 to 45% in the three component package. The polymericHALS may be present in an amount of between about 10 and 35% of thethree component package.

The moldable light stabilized polymeric composition of the presentinvention comprises TPO and a light stabilizer package. The lightstabilizer package comprises (1) a monomeric hindered amine lightstabilizer having a basicity or pKa of no greater than 7, (2) anultraviolet light absorbing agent and, optionally, (3) a polymerichindered amine light stabilizer having a basicity or pKa of less than 7.

Preferably the TPO of the present invention comprises a homopolymer anda copolymer of CH₂ ═C--(R)₂ where R is H or a C₁ -C₆ straight orbranched alkyl moiety, and, more preferably, comprises a homopolymer ofcrystalline polypropylene. Preferably, the TPO is a blend of crystallinepolypropylene and amorphous ethylene-propylene copolymer rubber.

Preferably, at least about 0.4 by weight of the light stabilizedpolymeric composition is the light stabilizer package. More preferably,the light stabilizer package is present in an amount of about 0.4-2% ofthe light stabilized polymeric composition of the present invention.

In these compositions, which can include either two component or threecomponent packages, the monomeric HALS may be present in an amount ofbetween about 0.1 and 1%, preferably between about 0.1 and 0.5%, thelight absorbing agent may be present in an amount of between about 0.1and 1%, preferably between about 0.1 and 0.5% and the polymeric HALS maybe present in an amount of between about 0.1 and 0.8%, preferablybetween about 0.1 and 0.4%.

Examples of the percentages of the components of the light stabilizerpackages that can be used in the light stabilized polymeric compositionsof the present invention are described in Table III.

                  TABLE III                                                       ______________________________________                                        LIGHT STABILIZED POLYMERIC COMPOSITIONS                                           Component    (% of polymeric composition)                                 ______________________________________                                                     Package 4  Package 5                                                                              Package 6                                    ______________________________________                                          Monomeric HALS 0.4 0.2 0.3                                                    UV Absorber 0.3 0.2 0.3                                                       Polymeric HALS 0.2 0.2 0.3                                                  ______________________________________                                           Package 7 Package 8 Package 9                                              ______________________________________                                          Monomeric HALS 0.3 0.3 0.3                                                    UV Absorber 0.3 0.2 0.3                                                       Polymeric HALS 0.1 0.2                                                      ______________________________________                                    

As noted above, the monomeric HALS may be present in an amount which isequal to or greater than the amounts of either of the light absorber orpolymeric HALS. Thus, the monomeric HALS may be present in a relativeamount of between 40 and 90% of the two component package, and betweenabout 30% and 80% of the three component package. The light absorbingagent may be present in an amount of between about 20 and 60% in the twocomponent package and between about 25 to 45% in the three componentpackage. The polymeric HALS may be present in an amount of between about10 and 35% of the three component package.

The article of the present invention has an exterior surface whichcomprises the moldable light stabilized polymeric composition of thepresent invention. At least a portion of the exterior surface of thearticle may be coated with one-pack coating comprising, for example, anacrylic, alkyd, melamine, polyester, thermoplastic or elastomericmaterial.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detailednon-limiting examples of the present invention.

EXAMPLE 1

In the following examples, various light stabilizer packages were mixedinto commercially available TPO's to form light stabilized polymericcompositions. Test plaques (4"×6"×1/8") were then injection molded andstudied.

EXAMPLE 2

The light stabilizer package described in Table IV was mixed with one oftwo TPO's to form a light stabilized polymeric composition.

                  TABLE IV                                                        ______________________________________                                        Light Stabilizer Packages                                                             Component  (% of package)                                             ______________________________________                                        Tinuvin ® 440                                                                            47.5                                                             Tinuvin ® 327 37.5                                                        Tinuvin ® 622 25.0                                                      ______________________________________                                    

The TPO's are either Dexflex® 980 of D&S Plastics, Inc. or Dexflex® 815of D&S Plastics Inc. Each of the two light stabilized polymericcompositions was painted with three different 1 pack paint systems andtested for TPO/paint interactions. Before painting, the test specimenswere first wiped with isopropyl alcohol and air blasted to remove thedust. After a five-minute flash, these specimens were coated with theadhesion promoter, then the base coat, and then, optionally, theclearcoat. Typical film thicknesses of these various coatings were0.1-0.3 mil for the adhesion promoter, 0.6-0.8 mil for the basecoat, and1.2-1.5 mil for the clearcoat. After painting, the specimens were curedin an oven at 120° C. for 30 minutes. Testing used to evaluate theTPO/paint interactions are as follows:

1. In the initial adhesion test, a clear cellophane adhesive tape,Nichiban® of Nichiban Co., Ltd., is used to pull on a 3 mm cross hatchedpaint surface;

2. In the gasoline immersion test, a synthetic gasoline mixture of 45%toluene and 55% naphthalene is used to soak the painted plaques. Paintlift and peeling is checked every half hour for up to six hours;

3. In the humidity test, the painted plaques are exposed for 240 hoursat 38°±2° C. to an atmosphere having 98%±2% relative humidity. Blisterrating is tested by visual observation according to ASTM D-714. Adhesionis tested by pulling on a 3 mm cross hatched surface with Permacel®masking tape of Permacel Corp. and, alternatively, with 1 inch wideScotch® filament tape, part no. 898, of 3M Packaging Systems Division.Targeting is for no loss of adhesion and a blister rating of 9 and abovefive minutes after completion of the exposure cycle.

4. In the water immersion test, the painted plaques are soaked in waterat 40° C. for 96 hours or at 38° C. for 240 hours. Blistering is testedby visual observation according to ASTM D-714. Adhesion is tested bypulling on 3 mm cross hatched surface with Permacel® masking tape ofPermacel Corp. and, alternatively, with 1 inch wide Scotch® filamenttape, part no. 898, of 3M Packaging Systems Division. Targeting is forno loss of adhesion and a blister rating of 9 and above five minutesafter completion of the exposure cycle.

The test results are summarized in Table V below.

                                      TABLE V                                     __________________________________________________________________________    EFFECT ON PAINTABILITY                                                                 TPO Compound                                                                          Dexflex 980                                                                             Dexflex 980                                                                            Dexflex 815                                                                            Dexflex 815                        Color Red Blue Natural Red                                                  Tests    Paint System                                                                          1   2  3  1  2  3  1  2  3  1  2  3                          __________________________________________________________________________    Tackiness        Heavy                                                                             None                                                                             None                                                                             None                                                                             None                                                                             None                                                                             Slight                                                                           None                                                                             None                                                                             None                                                                             None                                                                             None                         Init.  Fail Pass Pass Pass Pass Fail Pass Pass Fail Pass Pass Pass                                                              Adhesion                    Water Immersion                                                               40° C./96 Hr.                                                           Blister 9F 9F 9F 9F 9F 9F 9F 9F 9F 9F 10 9F                                   Permacel Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass                                                            898 Pass Pass Pass                                                          Pass Pass Pass Fail                                                           Pass Pass Fail Pass                                                           Pass                         Water Immersion                                                               38° C./240 Hr.                                                          Blister 9M 9M 8F 9M 9F 9F 9M 5F 9F 9M 9M 9F                                   Permacel Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass                                                            898 Fail Pass Pass                                                          Pass Pass Pass Pass                                                           Fail Pass Pass Pass                                                           Pass                         Humidity                                                                      38° C./240 Hr.                                                          Blister 9F 9F 9F 9M 9F 9F 9M 9M 9F 9F 9M 9F                                   Permacel Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass                                                            898 Pass Pass Pass                                                          Pass Pass Pass Pass                                                           Pass Pass Pass Pass                                                           Pass                         Gasoline Immersion  SC Pass Pass SC Pass Pass Pass In In CF In SC                                                               Test                      __________________________________________________________________________     Paint Systems:                                                                1. Adhesion PromoterMPP4110 of PPG Indus. Inc.; BasecoatCBC light blue        base of PPG Indus. Inc.; ClearcoatUCC1001 clear coat of PPG Indus. Inc.       2. Adhesion PromoterMPP4110 of PPG Indus. Inc.; BasecoatDWB Blue of PPG       Indus. Inc.; ClearcoatUCC1001 of PPG Indus. Inc.                              3. Adhesion PromoterMPP4110 of PPG Indus. Inc.; BasecoatBee 30 low gloss      primer of Morton Paint Co.                                                    Blister Quantity Ratings: (ASTM D714)                                         F = few; M = Medium; MD = Medium Dense; D = Dense                             Blister Size Ratings:                                                         10 = None; 9 = Micro; 8 = Pencil Point;                                       7 thru 1 = Increasing Larger                                                  Gasoline Immersion:                                                           In = Incipient Failure; CF = Catastrophic Failure; SC = Slight Curling        (only catastrophic failure is considered failure)                        

The data shows that the light stabilized composition of the presentinvention is less reactive toward 1-pack paint systems. Failure of thelight stabilized polymeric composition in the Initial Adhesion test forPaint System 3 is attributable to the aggressiveness of the paint systemrather than the light stabilizer package. This suggests that a lessaggressive paint system should be used for optimum results.

EXAMPLE 3

The light stabilizer packages described in Table VI were blended withDexflex 980 TPO to form light stabilized polymeric compositions.

                  TABLE VI                                                        ______________________________________                                        Light Stabilizer Packages                                                       (% of Package)                                                                         (% of Package)                                                     Component  Package 10  Package 11                                                                              Package 12                                   ______________________________________                                        Tinuvin ® 440                                                                        37.5                                                                 Tinuvin ® 327 25.0 25.0 37.5                                              Tinuvin ® 622 37.5 37.5 25.0                                              Tinuvin ® 123  37.5 37.5                                                ______________________________________                                    

The paintability of the light stabilized polymeric compositions wasdetermined using the same testing procedures as described in Example 2for the initial adhesion, gasoline soak and humidity tests, except thatthe humidity test was performed at 38° C. for 240 hours. The testresults are summarized in Table VII.

                  TABLE VII                                                       ______________________________________                                        EFFECT ON PAINTABILITY                                                                                      38° C./                                    Light Stabilized Paint Init. 240 Hr. 1 Hr. Gasoline                           Composition System Adhesion Humidity Immersion Test                         ______________________________________                                        Package 10 + TPO                                                                         1       Pass     Pass   Pass                                          2 Pass Pass Pass                                                              3 Pass Pass Pass                                                             Package 11 + TPO 1 Pass Pass Pass                                              2 Pass Pass Pass                                                              3 Pass Pass Pass                                                             Package 12 + TPO 1 Pass Pass Pass                                              2 Pass Pass Pass                                                              3 Pass Pass Pass                                                           ______________________________________                                         Paint Systems:                                                                1. Adhesion PromoterBee HP21054-4W1 of Morton Paint Co.; Basecoat872-9964     of E.I. DuPont de Nemours & Co., Inc.; ClearcoatRK3939 of E.I. DuPont de      Nemours & Co., Inc.                                                           2. Adhesion PromoterMPP-4110 of PPG Indus. Inc.; BasecoatUBC of PPG Indus     Inc.; ClearcoatUCC-1000 of PPG Indus. Inc.                                    3. Adhesion PromoterMPP-4110 of PPG Indus. Inc.; BasecoatBee UR560 of         Morton Paint Co.; ClearcoatBee Q65837 of Morton Paint Co.                

The results of the data shows that the light stabilized polymericcomposition of the present invention pass the initial adhesion, humidityand gasoline immersion tests.

EXAMPLE 4

The light stabilizer packages described in Table VIII were blended withDexflex 980 TPO to form light stabilized polymeric compositions.

                                      TABLE VIII                                  __________________________________________________________________________    Light Stabilizer Packages                                                       (% of Package)                                                              Component                                                                              Package 13                                                                          Package 14                                                                          Package 15                                                                          Package 16                                                                          Package 17                                                                          Package 18                                                                          Package 19                                                                          Package 20                 __________________________________________________________________________    Tinuvin ® 123                                                                      62.5  37.5  37.5  37.5  75.0  37.5  37.5  37.5                         Tinuvin ® 328 37.5 37.5 37.5 37.5 25.0 25.0 25.0 25.0                     Tinuvin ® 622  25.0    37.5                                               Chimmasorb ® 944    25.0    37.5                                          Chimmasorb ® 119   25.0    37.5                                         __________________________________________________________________________

The TPO/paint interactions of the various light stabilizers of TableVIII mixed with Dexflex 980 TPO was tested by the initial adhesion andhumidity test, using the same procedures as described in Example 3. Theresults are shown in Table IX.

                  TABLE IX                                                        ______________________________________                                        EFFECT ON PAINTABILITY                                                                                        Humidity                                        Polymeric Composition Init. Adhesion (240 Hr., 38° C.)               ______________________________________                                        Package 13 + TPO                                                                              Pass        Pass                                                Package 14 + TPO Pass Pass                                                    Package 15 + TPO Pass Fail (6/64)                                             Package 16 + TPO Pass Fail (5/64)                                             Package 17 + TPO Pass Pass                                                    Package 18 + TPO Pass Fail (5/64)                                             Package 19 + TPO Pass Fail (18/64)                                            Package 20 + TPO Pass Fail (12/64)                                          ______________________________________                                    

The results of the data shows that the light stabilized compositions ofthe present invention (compositions 13, 14 and 17) pass the humiditytest while the light stabilized compositions outside the scope of theclaimed invention (compositions 15, 16, 19 and 20) fail the humiditytest. Light stabilized composition 18, which is a light stabilizedcomposition of the present invention, failed the himidity test dueprobably to the presence of too much Tinuvin 622, having a pKa of 6.5,in comparison to the other components therein.

EXAMPLE 5

The light stabilizer packages described in Table X were blended withDexflex® 826 of D & S Plastics, Inc. to form light stabilized polymericcompositions. The light stabilized compositions of the present inventionwere compared against standard samples for paintability. The testprocedures were the same as described in Example 4, except that thehumidity test was performed at 38° C. for 240 hours. The results aresummarized in Table XI.

                  TABLE X                                                         ______________________________________                                        Light Stabilizer Packages                                                               (% of Package)                                                      Component Package 21   Package 22                                                                              Package 23                                   ______________________________________                                        Tinuvin 440                                                                             33                     50                                             Tinuvin 123  33                                                               Tinuvin 328 33 33 50                                                          Tinuvin 622 33 33                                                           ______________________________________                                    

                  TABLE XI                                                        ______________________________________                                        EFFECT ON PAINTABILITY                                                                          Paint    Init.   Humidity                                     Composition System Adhesion 240 Hr., 38° C.                          ______________________________________                                        Package 21 + TPO                                                                            1        Pass      Pass                                            2 Pass Pass                                                                  Package 22 + TPO 1 Pass Pass                                                   2 Pass Fail                                                                  Package 23 + TPO 1 Pass Pass                                                   2 Pass Fail                                                                  4.0% Carbon Black/No UV 1 Pass Pass                                            2 Pass Fail                                                                ______________________________________                                         Paint System                                                                  1. Adhesion PromoterHP-21054-4B1 Morton Paint Co.; BasecoatBAH-3 Red          Metallic of PPG Indus. Inc.; ClearcoatUCC-1001 of PPG Indus. Inc.             2. Adhesion PromoterHP-21054-4B1 of Morton Paint Co.;                         Basecoat89013-6-UR560 (White) of Morton Paint Co.                        

The results show that the light stabilized compositions of the presentinvention passes the initial adhesion test and passes the humidity testat the same rate as does the standard samples.

EXAMPLE 6

The light stabilizer system of the present invention is compared againstconventional light stabilizer systems and standard systems.

The components of the light stabilizer packages used in the lightstabilized polymeric compositions are described in Table XII. Thecomponents of the TPO's are described in Table XIII. The lightstabilized polymeric compositions are described in Table XIV.

                  TABLE XII                                                       ______________________________________                                        Light Stabilizer Polymeric Compositions                                                                        % of Component                                    in polymeric                                                               Package  Package composition                                                ______________________________________                                        A       high      Tinuvin ® 770                                                                          0.40                                               Cyasorb ® UV 531 0.40                                                     Cyasorb ® 944 0.40                                                      A medium Tinuvin ® 770 0.30                                                 Cyasorb ® UV 531 0.30                                                     Cyasorb ® 944 0.30                                                      A low Tinuvin ® 770 0.20                                                    Cyasorb ® UV 531 0.20                                                     Cyasorb ® 944 0.20                                                      B high Tinuvin ® 400 0.60                                                   Tinuvin ® 327 0.45                                                        Tinuvin ® 622 0.30                                                      B medium Tinuvin ® 400 0.40                                                 Tinuvin ® 327 0.30                                                        Tinuvin ® 622 0.20                                                      B low Tinuvin ® 400 0.20                                                    Tinuvin ® 327 0.15                                                        Tinuvin ® 622 0.10                                                    ______________________________________                                    

                  TABLE XIII                                                      ______________________________________                                        TPO                                                                                 TPO        Composition                                                                              % of TPO                                          ______________________________________                                        HiRb         Polypropylene                                                                            66                                                       Rubber 30                                                                     Carbon Black  4                                                              HiTa Polypropylene 56                                                          Rubber 20                                                                     Talc 20                                                                       Carbon Black  4                                                            ______________________________________                                    

The interaction between the light stabilized polymeric compositions ofTable XIV and paint systems were determined.

The initial adhesion test was performed the same as in Example 2. Thehumidity test was performed the same as in Example 2 except thatexposure was for 168 hours at 38° C. and 240 hours at 38° C. The waterimmersion test was performed the same as in Example 2, except that thepainted plaques were soaked for 168 hours at 38° C. and for 240 hours at38° C.

                                      TABLE XIV                                   __________________________________________________________________________    EFFECT ON PAINTABILITY                                                        __________________________________________________________________________            Hi Rb, no UV                                                                          Hi Rb, A-low                                                                          Hi Rb, A-high                                                                         Hi Rb, A-med                                  Paint System                                                                          1   2   1   2   1   2   1   2                                         __________________________________________________________________________      Tests                                                                         Initial Adhesion Pass Pass Pass Pass Pass Pass Pass Pass                      Water Immersion                                                              7 day  Pass                                                                              Pass                                                                              Failed after                                                                          Failed after                                                                          Failed after                                    10 day Pass Pass 1 day 1 day 1 day                                            Humidity                                                                       7 day Pass Pass Failed after Failed after Failed After                       10 day Pass Pass 1 day 1 day 1 day                                          __________________________________________________________________________            Hi-TA, no UV                                                                          Hi-TA, A-low                                                                          Hi TA, A-high                                                                         Hi Rb, B-med                                  Paint System                                                                          1   2   1   2   1   2   1   2                                         __________________________________________________________________________      Test                                                                          Initial Adhesion Pass Pass Pass Pass Pass Pass Pass Pass                      Water Immersion                                                              7 day  Pass                                                                              Pass                                                                              Failed after                                                                          Failed after                                                                          Pass                                                                              Pass                                        10 day Pass Pass 1 day 1 day Pass Pass                                        Humidity                                                                       7 day Pass Pass Failed after Failed after Pass Pass                          10 day Pass Pass 1 day 1 day Pass Pass                                      __________________________________________________________________________            Hi-TA, B-med                                                                          Hi Rb, B-low                                                                          Hi Rb, B-high                                                                         B-med                                         Paint System                                                                          1   2   1   2   1   2   1   2                                         __________________________________________________________________________      Tests                                                                         Initial Adhesion Pass Pass Pass Pass Pass Pass Pass Pass                      Water Immersion                                                                7 day Pass Pass Pass Pass Pass Pass Pass Pass                                10 day Pass Pass Pass Pass Fail Pass Pass Pass                                Humidity                                                                       7 day Pass Pass Pass Pass Pass Pass Pass Pass                                10 day Pass Pass Pass Pass Fail Pass Pass Pass                              __________________________________________________________________________     Paint System                                                                  1. Adhesion PromoterHP-21054-4B1 of Morton Paint Co.; Base coatUR560CAFH      vermillion 1K of Morton Paint Co.                                             2. Adhesion PromoterHP-21054-4B1 of Morton Paint Co.; Base coat89000-HC       UR560CAFH Wild Strawberry 1 of Morton Paint Co.; Clear coat  Q65837 of        Morton Paint Co.                                                         

The results show that show that the light stabilized compositions of thepresent invention provide significant improvement in light stabilityover the UV systems of the prior art.

Although the present invention has been described in detail, it isclearly understood that the same is by way of example only and is not totaken by way of limitation, the scope of the invention being limitedonly by the terms of the appended claims.

What is claimed is:
 1. A partially painted article having an exteriorsurface and comprising a molded light stabilized polymeric compositionthat does not interfere with acid curative coating systems, saidpolymeric composition comprising(a) a thermoplastic polyolefin; (b) amonomeric hindered amine light stabilizer having a basicity or pKa of nogreater than 7, said monomeric light stabilizer selected from the groupconsisting of polyalkyl piperidinyl acetamide compounds, polyalkylpiperidinyl ester compounds and triazaspiro-alkane-dione compounds; (c)a polymeric hindered amine light stabilizer of a polyalkylpiperidin-succinic acid copolymer having a basicity or pKa of no greaterthan 7; and (d) an ultraviolet light absorbing agent of a benzophenonecompound, wherein each of the monomeric hindered amine light stabilizer,the ultraviolet light absorbing agent and the polymeric hindered aminelight stabilizer are present in an amount effective to provide a stablesubstrate for an acid catalyst activated single component paint system,and wherein at least a portion of said surface is coated with said acidcatalyst activated single component paint system.
 2. The article ofclaim 1 wherein the coating comprises an acrylic, alkyd, melamine,polyester, thermoplastic or elastomeric material.
 3. The article ofclaim 1 wherein the light stabilizer package is present in an amount ofabout 0.4 to 2% by weight of the composition.
 4. The article of claim 1wherein the thermoplastic olefin comprises a homopolymer or copolymer ofCH₂ ═C--(R)₂ where R is H or a C₁ -C₆ straight or branched alkyl moiety.5. The article of claim 4 wherein the thermoplastic olefin comprisescrystalline polypropylene or polyethylene and at least one amorphouscopolymer.
 6. The article of claim 1 wherein the monomeric hinderedamine light stabilizer is a piperidine or piperazinone derivative havinga basicity or pKa of less than
 7. 7. The article of claim 1 wherein themonomeric hindered amine light stabilizer has a basicity or pKa ofbetween about 2.5 and
 5. 8. The article of claim 6 wherein the monomerichindered amine light stabilizer has a basicity or pKa of between about2.5 and
 5. 9. The article of claim 1 wherein the hindered amine lightstabilizer is present in an amount of between about 50 and 80% and theultraviolet light absorbing agent is present in an amount of betweenabout 20 and 50%.
 10. The article of claim 9 wherein the hindered aminelight stabilizer is present in an amount equal to or greater than theultraviolet light absorbing agent.
 11. The article of claim 1 whereinthe monomeric hindered amine light stabilizer is present in an amount ofbetween about 30% and 80%, the light absorbing agent is present in anamount of between about 10% and 45% and the polymeric hindered aminelight stabilizer is present in an amount of between about 10% and 35%.12. The article of claim 11 wherein the monomeric hindered amine lightstabilizer is present in an amount equal to or greater than the amountof the light absorbing agent and is present in an amount that is equalto or greater than the amount of the polymeric hindered amine lightstabilizer.
 13. The article of claim 1 wherein the monomeric hinderedamine light stabilizer is2,2,6,6-tetramethyl-4-(2-dodecyl-succinamidyl)-piperydinyl acetamide;bis (2,2,6,6-tetramethyl-1-(octyloxy)-4-piperydinyl) ester; or1,3,8-Triazaspiro(4.5)decane-2,4-dione.
 14. The article of claim 1wherein the polymeric hindered amine light stabilizer isN-(2-hydroxyethyl)-2,2,6,6-tetramethylpiperidin-4-ol-succinic acidcopolymer.
 15. A method of making a partially painted thermoplasticpolyolefin article that does not interfere with an acid curative coatingsystem, said method comprising the steps of:incorporating into athermoplastic polyolefin, (a) a monomeric hindered amine lightstabilizer having a basicity or pKa of no greater than 7, said monomericlight stabilizer selected from the group consisting of polyalkylpiperidinyl acetamide compounds, polyalkyl piperidinyl ester compoundsand triazaspiro-alkane-dione compounds; (b) a polymeric hindered aminelight stabilizer of a polyalkyl piperidin-succinic acid copolymer havinga basicity or pKa of no greater than 7; and (c) a light absorbing agentof a benzophenone compound; wherein each of the monomeric hindered aminelight stabilizer, the ultraviolet light absorbing agent and thepolymeric hindered amine light stabilizer are present in an amounteffective to provide a stable substrate for an acid catalyst activatedsingle component paint system; and painting at least a portion of saidstabilized thermoplastic polyolefin with an acid catalyst activatedsingle component paint system to form a stable, partially paintedthermoplastic polyolefin article.
 16. A method according to claim 15wherein the hindered amine light stabilizer is present in an amountgreater than or equal to the ultraviolet light absorbing agent.
 17. Amethod according to claim 15 wherein the monomeric hindered amine lightstabilizer is present in an amount of between about 30% and 80%, thelight absorbing agent is present in an amount of between about 10% and45% and the polymeric hindered amine light stabilizer is present in anamount of between about 10% and 35%.